Unfortunately, URL parameters aren't currently supported for YouTube videos in the Cascade builder. YouTube videos autoplay if you are using one on the cover or in an immersive section, but they don't loop. If you need a video to loop the easiest way to accomplish this is to upload your video to Vimeo as Cascade currently supports autoplay and looping for Vimeo videos.
We plan to add more options to Cascade in the future so that you can configure video behaviors like looping, autoplay, and start/end times in the builder rather than having to use URL parameters.
For now -- if you don't mind making an unsupported alteration to your story -- you can do what you want with a little hackery, as described below. There is some risk in doing this that you could break your story. I would recommend trying this procedure on a test story a few times first until you are comfortable with it before attempting on your real story.
- Using Cascade builder, find the place in your story where you want your looping YouTube video to appear and insert any web page (e.g., www.esri.com) using the Link to Content tab in the media picker.
- Save your story.
- Sign into the ArcGIS Online Assistant, which is a tool that lets you edit the JSON story definition stored in ArcGIS.
- At the top choose I want to...View an item's JSON.
- Find your story in the left panel and click it. The JSON code for your story map appears in the right panel.
- In the Data section of the right panel, find the URL you entered in step 1.
- Replace www.esri.com (or whatever URL you added in step 1) with the YouTube URL for your video that includes the URL parameters. Use the protocol relative format (don't include http: or https: -- the URL should just start with //www.youtube.com/...). See the example code below.
- Save the changes to the JSON using the save button at the top of the Data section.
- Reload your story to see your looping video.
If you want to use a YouTube video on the cover of your Cascade story you'll need to alter the procedure a bit...
In place of steps 6 and 7, copy the entire code snippet below and paste it in to replace the background section of your story's cover (which includes width, height, and the bracket on the next line, see below). Then replace the URL placeholder with the URL of your YouTube video with URL parameters, and save the changes to the JSON. Make sure all the pairs of brackets match up or the JSON won't validate and you won't be able to save.
"background": { "type": "webpage", "webpage": { "type": "webpage", "url": "//www.youtube.com/embed/..." }
For example, here's a before and after of the JSON:
Before
After
Owen Evans
Lead Product Engineer | StoryMaps